Stapled composite truss joist and method of assembly



Feb. 24,1970 A. L. TROUTNER STAPLED COMPOSITE'TRUSS JOIS'I' AND METHODOF ASSEMBLY Filed Sept. 23, 1968 ARTHUR L. TROUTNER INVENTOR BY 5 ATTY.

United States Patent 3,496,693 STAPLED COMPOSITE TRUSS JOIST AND METHODOF ASSEMBLY Arthur L. Troutner, Skyline Drive, Boise, Idaho 83702 FiledSept. 23, 1968, Ser. No. 761,751 Int. Cl. E04c 3/09 US. Cl. 52-693 3Claims ABSTRACT OF THE DISCLOSURE A structural truss joist for use insupporting roofs, floors, etc. includes two vertically spaced chordsdimensioned to span two horizontally spaced bearing walls. Each chordcomprises two spaced lumber pieces placed side by side parallel to eachother. A plurality of metal links are arranged zigzag between thechords. The ends of adjacent links overlap and extend between the lumberpieces comprising the chords. Registering openings extend through thepieces and each pair of overlapped link ends. Unsecured metal pinspenetrate the registering openings. Staples interconnect the lumberpieces comprising each chord, holding the pieces together, spacing themthe proper distance apart, and stabilizing the chords from bucklingunder compressive loads.

This invention relates to truss joists designed to carry heavy loads andto span substantial distances.

In my US. Patent No. 3,330,087 there is disclosed a heavy duty trussjoist of the class comprising upper and lower chords interconnected bywebbing of metal links arranged zig-zag between the chords. Each chordis a composite of two parallel pieces spaced laterally from each other.The ends of each pair of adjacent links are overlapped, inserted in thespace between the pieces comprising the chord, and fastened to eachother and to the pieces by pins penetrating registering opening throughall of these members. Securing means such as press on washers secure thepins, preventing them from becoming dislodged.

The foregoing tr-uss joist assembled is of great strength and has majorapplications. However, it is the purpose of the present invention toprovide a truss joist of the class described, but having materiallyimproved characteristics and functions, as follows:

(1) It maintains an accurate spacing between the pieces comprising therespective chords.

(2) It holds'the pieces together securely.

(3) It eliminates the securing washers or other externally projectingfasteners for securing the pins to the chords. This in turn makespossible the provision of truss joists having flush side faces, withoutprojecting metal parts.

(4) It includes chords which are stabilized from buckling undercompressive loads.

(5) It may include chords composited from lumber pieces of smaller sizeand lower grade without sacrifice of truss joist properties, therebydecreasing the cost of the final product.

(6) It maybe made lighter, without sacrifice of strength, therebyfacilitating and rendering less expensive its handling, transportationand application to various construction projects.

(7) Its assembly at the plant is greatly simplified, increasingproduction and reducing labor costs.

The manner in which the foregoing and other objects of the invention areaccomplished will be apparent from the accompanying specification andclaims considered together with the drawings, wherein:

FIG. 1 is a fragmentary view in side elevation of the herein describedstapled, composite truss joist;

3,496,693 Patented Feb. 24, 1970 FIGS. 2, 3 and 4 are fragmentarysectional views taken along lines 2, 3 and 4 respectively of FIG. 1; and

FIG. 5 is a view in elevation of a staple element employed in theconstruction of the truss joist illustrated in the preceding figures.

Generally stated, the stapled, composite truss joist of my inventioncomprises a structural truss joist for use in supporting roofs, floors,etc. It includes two vertically spaced chords dimensioned to span twohorizontally spaced bearing walls. Each chord comprises two spacedlumber pieces placed side by side parallel to each other.

A plurality of metal links are arranged zig-zag between; the chords,with the ends of adjacent links overlapped and extending between thelumber pieces comprising the chords. Registering openings extend throughthe pieces and each pair of overlapped link ends. Unsecured metal pinspenetrate the registering openings.

Staples interconnect the lumber pieces comprising each chord, holdingthe pieces together, spacing them the proper distance apart, andstabilizing the chords from buckling under compressive loads.

Considering the foregoing in greater detail and with particularreference to the drawings:

As indicated in FIG. 1, the stapled, composite truss joists of myinvention are supported in parallel, spaced arrangement between a pairof bearing walls, one of which is indicated at 4. The bearing walls maybe of wood, concrete, or masonry construction. A wooden or other bearingplate 6 may lie across the top of each bearing wall.

Each joist is composed of an upper chord, indicated generally at 10, anda lower chord, indicated generally at 12. In one embodiment, upper chord10 is longer than lower chord 12. Its ends overlie and are supported bvthe bearing plate.

Lower chord 12 is slightly shorter than the distance between the bearingwalls 4 spanned by the joists. It is not supported directly thereby, butis nailed or otherwise fastened to a stabilizing strip 14 mounted on theinside surface of the bearing Walls.

To supply the requisite strength and length, while using a minimum oflumber, each of chords 10, 12 is a composite of two structural piecesplaced side by side, parallel to each other, and spaced aparthorizontally to provide an intermediate space of predetermined width, asrequired to accommodate linking members.

Thus, in the case of a medium high-load truss joist, each chord may be acomposite of a pair of 2 x 3 pieces placed on edge; the piecescomprising upper chord 10 are indicated at 15, 16. Lower chord 12 may beconstituted similarly.

Upper chord 10 and lower chord 12'are interconnected by a lacing of linkmembers arranged zig-zag with their ends overlapped. Each link membermay comprise a metal tube 20 having transversely perforated flat ends22. The latter are of such thickness that when overlapped they may beinserted in the space between the pieces comprising each chord as shownparticularly in FIGS. 2 and 3.

At spaced offset intervals, which may be longer and farther apart thanthe intervals of the truss joist of my US. Patent No. 3,330,087aforesaid, the upper and lower chords are cross bored to form openingswhich register with the perforations through the flattened ends 22 ofthe link members.

Pin means are inserted through the registering Openings to interconnectthe link members and the chords. The construction of the pin meansemployed is illustrated particularly in FIG. 3.

As illustrated in that figure, each pin means may comprise a hollowcylinder 24 dimensioned for snugly fitting reception in the registeringcross bores through the lumber pieces and the perforations through theflat link ends.

3 The ends of the cylinders lie flush, or are slightly recessed in, theexterior side faces of the chord.'They do not project outwardly. Beyondthe frictional engagement supplied by the snug fit, no extraneousfasteners secure the pins to the lumber pieces and links. In otherwords, the ins are unsecured in their respective chord-link assemblies.

The key feature of the herein described composite truss joist, and thatwhich distinguishes them in structure and properties from the trussjoist of the prior art, is the provision of a plurality of staples 30which are driven into the pairs of lumber pieces comprising each chord.The staples interconnect the pieces and maintain them separated by aspaced distance.

As illustrated in FIG. 5, the staples are of the heavy duty structuralclass designed to carry a substantial load. To fix them securely inpiace, their terminal portions preferably are serrated. The weight anddimensions of the staples may be varied to suit particular applications.

However, where 2x35 are employed as the lumber pieces comprising thechord, the staples may comprise 1% inch heavy duty metal staples.

Similarly, the spacing of the staples from each other may be varied tosuit the particular properties demanded of the final product. However,in a typical product, the staples may be placed on the top and bottom ofthe chords opposite each other, on each side of each panel point. Thisarrangement is shown particularly in FIG. 1.

The stapled truss joists of my invention are easily manufactured. First,the lumber pieces making up the chords are positioned with thepredetermined lateral spacing in a suitable jig or holder. Next, thestaples are driven into 'the pieces at the desired locations,maintaining the spacing. Next the connecting web .of links is insertedinto the spaces thus provided, aligned, and the pins driven through theresulting assembly. This completes the manufacture of the truss joist.

Manifold benefits flow from the application of the product and methoddescribed above. The truss joists are stabilized against buckling undercompressive loads by the presence of the staples so that desired ratingsare maintained using lighter weight chords of lower grade lumber. Theindividual links are locked in by the wood 1. A composite truss joistcomprising "(a) two 'vertically spaced chords/dimensioned to span twohorizontally spaced bearing walls,

(bf: each chord comprising two juxtaposed lumber pieces placed side byside and parallel to each other,

(c) a plurality of links arranged in zig-zag relation between the chordswith the ends of adjacent links overlapped and extending between thelumber pieces comprising the chord,

(d) there being registering openings through the pieces and each pair ofoverlapped link ends,

(e) unsecured metal pin means penetrating the registering openings,securing together the links and pieces, forming panel points,

(f) and staple means driven into the pieces comprising each chord atspaced intervals, on each side of each panel point, thereby maintainingthe pieces in their spaced apart relation, maintaining the overlappedlinks and pins in their assembled condition, and stabilizing the chordsfrom buckling under compressive loads.

2. The truss joist of claim 1 wherein the staples are spacedsubstantially opposite each other, top and bottom of the chords, onepair on each side of each panel point.

3. The method of compositing a structural truss joist which comprises(a) positioning a pair-of lumber pieces in laterally spaced relation toeach other.

(b) stapling the pieces together while maintaining the spaced relationbetween them, thereby producing a composite chord,

(c) arranging two of the composite chords in spaced apart upper andlower chord relation;

((1) arranging interconnecting links zig-zag between the chords with theends of adjacent ones of the links overlapped and inserted in the spacebetween the pieces comprising each chord,

(e) the link ends and adjacent chord areas having registered openingstherethrough, and

(f) inserting pins through the registering openings,

thereby assembling the composite truss joist.

References Cited UNETED STATES PATENTS JOHN E. MURTAGH, Primary ExaminerU.S. Cl. X.R. 29-155, 432, 526

